Casing for mechanisms



July 20 G. M. PROUDFOOT CASING FOR IIECHANISIS Filed August 1, 1924 Patented July 20,1926.

UNITE-D v.s mass P "E NT FF! (15E GORDON/M. rnonuroo r, "or CHICAGO, ILLINOIS, ASSIGNOR "r0 CRLTVER MANUFAC- I TIT-RING BOMPANLOF CHICAGO, ILLINOIS, .TA CORPORATION OF ILLINOIS.

CASING non MECHANISMS.

application filed August 1,";1924. Serial No. 729,483.

This invention relates to housings for radio condensers and other mechanisms, including =a, preferably, transparent portion, wherein said transparent portion may be easily removed and replaced *without requiring disassembling of the housing or the removal or manipulation of any fastening or retaining devices for said transparent portion and wherein the latter consists of a flexible substance, such as sheet-celluloid incapable of being splintered and thus causing particles thereof to become lodged in the mechanism housed thereby and which, at the same time is so associated with permanent housing elements as to provide a substantially dust proof casing for the said mechanism.

The preferred embodiment of the invention is illustrated in the accompanying drawings, wherein:

Fig. 1 is a perspective viewcof a radio condenser (as exemplary of a mechanism) equipped with a housing constructed in accordance with the invention.

Fig. 2 is a transverse section of the same.

Fig. 3 is a fragmentary radial section of the same on the line 33 of Fig. 2.

Figs. 4: and 5 are, respectively, a fragmentary plan view and side elevation of the flexible, transparent element of the housing.-

The invention relates more particularly to housing which include a peripheral or circumferential wall or wall portion bordered by end-plates or other permanent parts of the mechanism per se or constitute housing elements more or less permanently associated with the mechanism.

In the instance illustrated, the mechanism consists of a radio-condenser substantially identical with that illustrated and described in my pending application for United States Letters Patent, Serial No. 695,889, filed February 29, 1924, but may be also applied. for example, to spring or other instruments of precision of various types.

In the instance illustrated, the mechanism or its housing, includes two circular end plates A provided in their opposed faces with annular grooves B disposed closely contiguous to and concentric with their peripheral or circumferential edges. Said plates are suitably permanently spaced from each other and are usually, as in the instance illustrated, parallel.

The transparent housing element consists of 'a strip C of a flexible material, such as sheet celluloid, of :a width substantially equal to the distance between the bottoms of 'the or peripheral length of said grooves, one ex treme end portion ofsaid strip G suitably permanently rendered concavo-convex, as at D, the convex face of said portion being a part of the Outer or exposed face of the strip G when engaged along its side edges in the grooves B. The strip C is normally straight and is, as indicated in dotted lines in Fig. 3, slightly bowed transversely preparatory to starting the side edges of the end thereof opposite to the end-portion D, into the grooves B, said bowing being temporarily digitally effected to first decrease the spacing of said side edges of said strip to slightly less than the distance between the opposed faces of the plates A. This bowing of the strip C is gradually continued throughout the length thereof simultaneously with eifecting digital curving thereof to thereby gradually continuously effect a springing of its side edge portions into said grooves B, the latter being preferably of a width substantially double the thickness of the sheet G.

The end-portion D is adapted to overlap the other end portion of the strip G, as shown in Fig. 2, and, to effect insertion of the side edges of said portion D into the grooves B it isnecessary to digitally flatten out the same, this being digitally accomplished and subsequently maintained by said grooves. The end terminals of said por tion D, as well as the lengthwise edge thereof, are thus maintained in firm contact with the outer face of the other end portion of the strip C by the frictional engagement of the outer faces of the end terminals of the portion D with the outer walls of the grooves B, and thus serves to produce a substantially sealed joint at this point.

The strip C is easily removed by insertion of a finger-nail or knife-edge under the last mentioned or overlapping end thereof and just pulling the strip away in the same manner as adhesive tape is unwound from a roll and may be removed and replaced as often as necessary or desirable without injury thereto.

Obviously other materials, such as paper, for example, may be substituted for the celluloid if transparency is not required and it is desired to reduce expense.

I claim as my invention:

A casing for the purpose set forth comprising a pair of end plates suitably connected together, spaced from each other and each having its inner face formed with an annular groove in proximity to its edge, and a removable flexible strip forming the body portion of the casing and 01' a width greater than the space between said plates, said strip adapted to be bowed between its side edges progressively to provide for the progressive springing of its side edges from 1 its end into said grooves to form the strip of annular contour with the end terminal por- 'tions thereof overlapping, each of said grooves of a width substantially twice the thickness of said strip, the outer overlapping end terminal portion of said strip bowed transversely and having the end terminal portions thereof frictionally engaging with the outer walls of said grooves to produce a substantially sealed joint between the lengthwise edge oi said bowed portion and the body of the strip, said bowed portion further providing means to permit of the removal of the strip from said end plates.

GORDON M. PROUDFOOT. 

